The present invention generally relates to a hot water dispenser, and more particularly to a hot water dispenser for dispensing a selected volume of water having a preselected temperature.
Various types of hot water dispensers are known in the prior art. Many of the known dispensers are complex and expensive in construction. For example, U.S. Pat. No. 3,326,417 issued June 20, 1967 discloses an automatic liquid dispensing machine including a cup movable in a vertical path from a lower discharge position to a filling and heating position thereabove. The cup has a discharge opening in its bottom through which liquid may be discharged, with a liquid reservoir having a discharge passageway for introducing liquid into the cup. A heating element associated with said cup for heating liquid within said cup, a detent for latching the cup in the heating or filling position, a thermostat actuated by the temperature of liquid within said cup for actuating the detent to release the cup when the liquid has reached a prescribed temperature. A valve is actuated by movement of the cup for closing the discharge opening upon upward movement of said cup and for opening the discharge opening upon downward movement of said cup. The valve is also operative for opening the discharge passageway from the reservoir for supplying a measured amount of liquid from the reservoir to the cup when said cup is moved upwardly.
U.S. Pat. No. 4,459,465 discloses an instantaneous water heater which has a plurality of thermostat-controlled heating elements, with an electrical contactor wired in series between each respective heating element and thermostat, which contactor acts both as a temperature control and, with the contactors acting in series with each other, as a safety shut-off control.
Generally, prior coffee brewing and hot water dispensing systems have used reservoirs to pre-measure the quantity of water desired. This is the case with the U.S. Pat. No. 3,333,527 issued to Bender and the U.S. Pat. No. 4,000,396 issued to Abel, Jr. These systems isolate the quantity desired from any fluctuation in inlet pressure or temperature. Of course, this reservoir system prohibits a compact design and makes it impractical without accurate flow control and measuring devices to directly connect the system to a water line.
In the U.S. Pat. No. 3,948,156 issued to Smith, there is described an apparatus for direct connection to a water line. This system provides a pressure regulator and flow control to deliver a precise quantity of water to the heater during a timed interval. Additionally, the power to the heater is controlled in response to the inlet temperature of the water to regulate the outlet temperature to eliminate steam. No prior art device has been suggested which is operable without all these controls, allows direct connection to a water supply line, and will deliver reliable quantities of hot water.
Accordingly, a need exists to provide a hot water dispenser that is relatively simple in construction, economical to manufacture and both effective and efficient in operation.
Moreover, a long felt need has been demonstrated for a coffee brewing apparatus which is directly connectable to a water line, and which delivers reliable quantities of water, independent of inlet temperature and pressure and independent of line voltage.